While the US is breaking population records, states such as Illinois and West Virginia have lost people in recent years.  Something similar is happening in the US crude oil futures market. Even as it surpasses 2bn barrels in total, certain precincts have quietly thinned out.  The number of outstanding oil contracts for delivery years into the future has plummeted on the New York Mercantile Exchange. Since 2012 open interest has declined by more than 75 per cent for benchmark West Texas Intermediate crude expiring in three or four years’ time. During the same period the entire WTI market has expanded by 40 per cent.  The crosswise trends may be an unheralded effect of the US shale oil revolution. Able to quickly ramp volumes up or down, unconventional producers have less need to hedge against price swings years away. Prolific supplies have also caused fund managers to think twice before making long-term bets on oil.  “Five or 10 years ago there was a much more bullish consensus further out the curve,” says Michael Guido, managing director of hedge fund energy sales at Macquarie, one of the biggest banks in commodities markets. The open interest “disappeared because of the reality of what happened with shale”.